The FDA "does not condone any form of employee retaliation," a statement said.
Graham, 50, is the associate director for science and medicine in the FDA's Office of Drug Safety. The office is part of the Center for Drug Evaluation and Research, which is also responsible for applications to market new drugs. He told the Senate that of 12 drugs he had investigated for problems, 10 had been taken off the market.
"He is a good scientist who does careful work," said Dr. Paul Stolley, former chairman of preventive medicine at the University of Maryland who worked with Graham at the FDA in 2000 and 2001. "When there are attempts to intimidate him, he resists. But he is not a bomb thrower. He is a good citizen and a steady guy."
Relations between Graham and his superiors appear to have been especially strained since the summer, when he sought to present study findings at a medical conference indicating a potential problem with Vioxx. He said they tried to block publication of his findings in a journal.
FDA officials said Graham did not follow agency procedures in submitting his journal article. As for the conference, they pointed out that he was able to attend and present his results, which indicated an increase in heart problems among patients on high doses of Vioxx.
Neither the FDA nor Merck regarded those findings as conclusive. However, after a Merck-sponsored clinical trial found similar results, the company withdrew the drug from the market.
Graham said the attempt to shift him out of the Drug Safety Office began before his Senate testimony last week. On Nov. 9, he said, acting FDA Commissioner Lester M. Crawford asked him to consider a new assignment as part of a team reviewing the workings of the agency.
Graham said he told Crawford that he would not be interested, and the commissioner did not press the matter. However, Graham said he has recently heard unofficially that he will be ordered to take a new assignment.
"I will be saddled with administrative duties that a scientist doesn't do," he said. "It's a way of neutralizing me so I won't be able to expose any additional drugs."
Devine said Graham could decline the transfer, "but he would be fired for insubordination."
The government does have some protections for whistle-blowers. A special office investigates their complaints and can reverse punitive personnel actions. But whistle-blowers face a lonely existence in the bureaucracy, often relegated to lesser duties while their complaints are investigated.
Devine, Graham's lawyer, said colleagues gave the scientist a round of applause when he returned to the office after his Senate testimony. Such publicly expressed acclaim for a whistle-blower is unusual, said Devine.
"Usually, you only get that kind of reaction in the bathroom," he said.
